Avoid manual unroll of non-hot SipHash loops

As these loops will be executed only once for every #hash invokation,
it would make sense to defer the decision to unroll the loops to the
runtime.
Hoist SipHashInline range checks

In principle, this should allow the JIT compiler to remove all range
checks within the loop. I haven't had time to verify this though.
Use Unsafe to read a long at a time

While one could wish that JIT compilation optimised the eight sequential
byte reads into a single long read, it in fact does not.

This implementation should fallback to the slow implementation in a
context where Unsafe fails to load, but I haven't figured out how to
test that properly.
Deprecate overloaded `setProfile`, prefer `setProfilingMode`

The ScriptingContainer class contains two methods named `setProfile`,
which differ only by their single argument type and do very different
things from one another.  One of the two signatures accepts
an argument of type `ProfilingMode`, which, in other places in the
code, is exposed via more explicitly named accessor methods such as
`getProfilingMode` and `setProfilingMode`.  I'm wondering if maybe
the method in `ScriptingContainer` was simply accidentally mis-named.

This commit deprecates the `setProfile(ProfilingMode)` method, and
introduces a replacement method `setProfilingMode(ProfilingMode)`,
which is more consistent with the rest of the code.
tweak include order
Implemented multi args 'system' method on Windows

'system' method of multi args was not able to support
Windows internal commands.
(ex) echo, cd, etc
fixed issue 1695
fix enums to return nil on unknown symbol
sync/update ffi specs
fix failing variadic spec

updates variadic invoker to match MRI
variadic functions may now take enum arguments
fix failing syslog test

also adds ffi spec for failure
[build] keep in sync with master
[build] fix the osgi and complete profile to pick the right stuff
[build] * run install goal on maven-integration-tests
* make sure changes in src/templates will be used with out mvn clean
make the test if native is loaded more robust
Merge branch 'jruby-1_7' of jruby.org:jruby into jruby-1_7
[build] fix the exclude for jdk6
improve handling of non ascii character after backslash
Made Exception#set_backtrace compliant with Ruby documentation by supporting single Strings.
Fixed spacing